1/*
2 * HID driver for ELO usb touchscreen 4000/4500
3 *
4 * Copyright (c) 2013 Jiri Slaby
5 *
6 * Data parsing taken from elousb driver by Vojtech Pavlik.
7 *
8 * This driver is licensed under the terms of GPLv2.
9 */
10
11#include <linux/hid.h>
12#include <linux/input.h>
13#include <linux/module.h>
14#include <linux/usb.h>
15#include <linux/workqueue.h>
16
17#include "hid-ids.h"
18
19#define ELO_PERIODIC_READ_INTERVAL	HZ
20#define ELO_SMARTSET_CMD_TIMEOUT	2000 /* msec */
21
22/* Elo SmartSet commands */
23#define ELO_FLUSH_SMARTSET_RESPONSES	0x02 /* Flush all pending smartset responses */
24#define ELO_SEND_SMARTSET_COMMAND	0x05 /* Send a smartset command */
25#define ELO_GET_SMARTSET_RESPONSE	0x06 /* Get a smartset response */
26#define ELO_DIAG			0x64 /* Diagnostics command */
27#define ELO_SMARTSET_PACKET_SIZE	8
28
29struct elo_priv {
30	struct usb_device *usbdev;
31	struct delayed_work work;
32	unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
33};
34
35static struct workqueue_struct *wq;
36static bool use_fw_quirk = true;
37module_param(use_fw_quirk, bool, S_IRUGO);
38MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
39
40static void elo_input_configured(struct hid_device *hdev,
41		struct hid_input *hidinput)
42{
43	struct input_dev *input = hidinput->input;
44
45	set_bit(BTN_TOUCH, input->keybit);
46	set_bit(ABS_PRESSURE, input->absbit);
47	input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
48}
49
50static void elo_process_data(struct input_dev *input, const u8 *data, int size)
51{
52	int press;
53
54	input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
55	input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
56
57	press = 0;
58	if (data[1] & 0x80)
59		press = (data[7] << 8) | data[6];
60	input_report_abs(input, ABS_PRESSURE, press);
61
62	if (data[1] & 0x03) {
63		input_report_key(input, BTN_TOUCH, 1);
64		input_sync(input);
65	}
66
67	if (data[1] & 0x04)
68		input_report_key(input, BTN_TOUCH, 0);
69
70	input_sync(input);
71}
72
73static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
74	 u8 *data, int size)
75{
76	struct hid_input *hidinput;
77
78	if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
79		return 0;
80
81	hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
82
83	switch (report->id) {
84	case 0:
85		if (data[0] == 'T') {	/* Mandatory ELO packet marker */
86			elo_process_data(hidinput->input, data, size);
87			return 1;
88		}
89		break;
90	default:	/* unknown report */
91		/* Unknown report type; pass upstream */
92		hid_info(hdev, "unknown report type %d\n", report->id);
93		break;
94	}
95
96	return 0;
97}
98
99static int elo_smartset_send_get(struct usb_device *dev, u8 command,
100		void *data)
101{
102	unsigned int pipe;
103	u8 dir;
104
105	if (command == ELO_SEND_SMARTSET_COMMAND) {
106		pipe = usb_sndctrlpipe(dev, 0);
107		dir = USB_DIR_OUT;
108	} else if (command == ELO_GET_SMARTSET_RESPONSE) {
109		pipe = usb_rcvctrlpipe(dev, 0);
110		dir = USB_DIR_IN;
111	} else
112		return -EINVAL;
113
114	return usb_control_msg(dev, pipe, command,
115			dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
116			0, 0, data, ELO_SMARTSET_PACKET_SIZE,
117			ELO_SMARTSET_CMD_TIMEOUT);
118}
119
120static int elo_flush_smartset_responses(struct usb_device *dev)
121{
122	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
123			ELO_FLUSH_SMARTSET_RESPONSES,
124			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
125			0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
126}
127
128static void elo_work(struct work_struct *work)
129{
130	struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
131	struct usb_device *dev = priv->usbdev;
132	unsigned char *buffer = priv->buffer;
133	int ret;
134
135	ret = elo_flush_smartset_responses(dev);
136	if (ret < 0) {
137		dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
138				ret);
139		goto fail;
140	}
141
142	/* send Diagnostics command */
143	*buffer = ELO_DIAG;
144	ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
145	if (ret < 0) {
146		dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
147				ret);
148		goto fail;
149	}
150
151	/* get the result */
152	ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
153	if (ret < 0) {
154		dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
155				ret);
156		goto fail;
157	}
158
159	/* read the ack */
160	if (*buffer != 'A') {
161		ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
162				buffer);
163		if (ret < 0) {
164			dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
165					ret);
166			goto fail;
167		}
168	}
169
170fail:
171	ret = elo_flush_smartset_responses(dev);
172	if (ret < 0)
173		dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
174				ret);
175	queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
176}
177
178/*
179 * Not all Elo devices need the periodic HID descriptor reads.
180 * Only firmware version M needs this.
181 */
182static bool elo_broken_firmware(struct usb_device *dev)
183{
184	struct usb_device *hub = dev->parent;
185	struct usb_device *child = NULL;
186	u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
187	u16 child_vid, child_pid;
188	int i;
189
190	if (!use_fw_quirk)
191		return false;
192	if (fw_lvl != 0x10d)
193		return false;
194
195	/* iterate sibling devices of the touch controller */
196	usb_hub_for_each_child(hub, i, child) {
197		child_vid = le16_to_cpu(child->descriptor.idVendor);
198		child_pid = le16_to_cpu(child->descriptor.idProduct);
199
200		/*
201		 * If one of the devices below is present attached as a sibling of
202		 * the touch controller then  this is a newer IBM 4820 monitor that
203		 * does not need the IBM-requested workaround if fw level is
204		 * 0x010d - aka 'M'.
205		 * No other HW can have this combination.
206		 */
207		if (child_vid==0x04b3) {
208			switch (child_pid) {
209			case 0x4676: /* 4820 21x Video */
210			case 0x4677: /* 4820 51x Video */
211			case 0x4678: /* 4820 2Lx Video */
212			case 0x4679: /* 4820 5Lx Video */
213				return false;
214			}
215		}
216	}
217	return true;
218}
219
220static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
221{
222	struct elo_priv *priv;
223	int ret;
224
225	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
226	if (!priv)
227		return -ENOMEM;
228
229	INIT_DELAYED_WORK(&priv->work, elo_work);
230	priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
231
232	hid_set_drvdata(hdev, priv);
233
234	ret = hid_parse(hdev);
235	if (ret) {
236		hid_err(hdev, "parse failed\n");
237		goto err_free;
238	}
239
240	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
241	if (ret) {
242		hid_err(hdev, "hw start failed\n");
243		goto err_free;
244	}
245
246	if (elo_broken_firmware(priv->usbdev)) {
247		hid_info(hdev, "broken firmware found, installing workaround\n");
248		queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
249	}
250
251	return 0;
252err_free:
253	kfree(priv);
254	return ret;
255}
256
257static void elo_remove(struct hid_device *hdev)
258{
259	struct elo_priv *priv = hid_get_drvdata(hdev);
260
261	hid_hw_stop(hdev);
262	flush_workqueue(wq);
263	kfree(priv);
264}
265
266static const struct hid_device_id elo_devices[] = {
267	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
268	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
269	{ }
270};
271MODULE_DEVICE_TABLE(hid, elo_devices);
272
273static struct hid_driver elo_driver = {
274	.name = "elo",
275	.id_table = elo_devices,
276	.probe = elo_probe,
277	.remove = elo_remove,
278	.raw_event = elo_raw_event,
279	.input_configured = elo_input_configured,
280};
281
282static int __init elo_driver_init(void)
283{
284	int ret;
285
286	wq = create_singlethread_workqueue("elousb");
287	if (!wq)
288		return -ENOMEM;
289
290	ret = hid_register_driver(&elo_driver);
291	if (ret)
292		destroy_workqueue(wq);
293
294	return ret;
295}
296module_init(elo_driver_init);
297
298static void __exit elo_driver_exit(void)
299{
300	hid_unregister_driver(&elo_driver);
301	destroy_workqueue(wq);
302}
303module_exit(elo_driver_exit);
304
305MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
306MODULE_LICENSE("GPL");
307